"I personally believe that like time travel, both technologies will never truly exist."

Well there's a pretty big difference between the two. Technology for time travel cannot exist because the rules of nature as we understand them don't permit it. I don't think anybody would claim that physics rules out artificial intelligence in the same way.

"I believe we can mimic intelligence, but I don't believe computers will be able to grasp 'though' as we do, not now, not in another 30 years, not ever."

I'd like you to define precisely what you consider to be "intelligent". It seems there's a strong tendency to shift goalposts in the field of AI.

Like zima already said, there's a risk of setting the bar so high as to rule out animals and humans. If we're to be objective, our litmus tests shouldn't focus around humans proficiencies but instead be inclusive of any intelligent life in the universe.

Here's a challenge: come up with a satisfactory litmus test that animals and humans can pass but ultimately computers cannot.